Could Quantum Computing Render Blockchain Security Meaningless?

There exists a race further develop two fairly recent technologies: decentralized blockchains (Bitcoin being the most notable example) and quantum computing. Blockchain technology promises to deliver secure, transparent, and immutable transactions between multiple parties and usher in an age where traditional financial institution are rendered unnecessary.

Some pundits have even argues that blockchain and cryptocurrency technologies are set to have a greater impact on society than the internet itself. Where as quantum computing, in principle, could solve mathematical problems in minutes that would take classical computer thousands upon thousands of years to solve. This technology will have the potential provide human kind with unparalleled processing power to tackle some of the most challenging problems. It has the potential to change the global financial system as we know it.

Using history as a guide, technological advances can often be a two-edged sword. Atomic research, for example, has provided much of energy to meet needs with developed economies. But there are environmental and health risks associated with the usage and disposal of nuclear materials; and there remains the specter armed conflict between nations with nuclear capable weapons within their arsenals. So it is with the advances surrounding quantum computing that one has to consider possible risks associated with that technology.

Bad actors. This could include hostile governments, organized crime, rogue elements within legitimate governments, individuals engaged in corporate espionage, etc. I think you get the picture. History is replete with examples of whenever or whereever there is lots of wealth to be had, crime and violence will certainly follow. If blockchains and the cryptocurriencies riding on top of them are to become the foundation upon which the world's new economies constructed and if quantum computing can render security current mechanisms useless, then, by what means will blockchains be able to defend against these bad actors and other potential treats?

Quantum Blockchains

Quantum cryptography is a field of research (based on quantum mechanics) that seeks to add an uncrackable layer of security to blockchains. The laws of physics will ensure the integrity of data and protect access to that data through a mechanism based on quantum entanglement. After their formation, two subatomic particles share entangled properties (regardless of distance involved) and if one of the particles is disturbed, symmetry is broken and partner particle is forced to assume an opposite state. Researchers, such as Del Rajan and Matt Visser at the Victoria University of Wellington in New Zealand, are experimenting with recording block entries onto quantum bits. Any attempts to tamper with data on the blockchain will cause the blockchain to become invalid. Similar technology could also provide foolproof encryption for carrying out transaction between differing blockchains.

If public blockchain technology is to attain a similar growth trajectory of the internet, or even surpass it, it is obvious that as quantum computing online, blockchain technology must blend with quantum computing to remain a viable solution for the future.

A very interesting article covering this topic in much greater detail can be found at MIT Technology Review.